/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.actionbarsherlock.widget;

import android.app.SearchManager;
import android.content.ComponentName;
import android.content.ContentResolver;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.database.Cursor;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.widget.ResourceCursorAdapter;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.TextUtils;
import android.text.style.TextAppearanceSpan;
import android.util.Log;
import android.util.TypedValue;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.actionbarsherlock.R;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.WeakHashMap;

/**
 * Provides the contents for the suggestion drop-down list.
 *
 * @hide
 */
class SuggestionsAdapter extends ResourceCursorAdapter implements OnClickListener {

  private static final boolean DBG = false;
  private static final String LOG_TAG = "SuggestionsAdapter";
  private static final int QUERY_LIMIT = 50;

  static final int REFINE_NONE = 0;
  static final int REFINE_BY_ENTRY = 1;
  static final int REFINE_ALL = 2;

  @SuppressWarnings("unused")
private SearchManager mSearchManager;
  private SearchView mSearchView;
  private Context mProviderContext;
  private WeakHashMap<String, Drawable.ConstantState> mOutsideDrawablesCache;
  private boolean mClosed = false;
  private int mQueryRefinement = REFINE_BY_ENTRY;

  // URL color
  private ColorStateList mUrlColor;

  static final int INVALID_INDEX = -1;

  // Cached column indexes, updated when the cursor changes.
  private int mText1Col = INVALID_INDEX;
  private int mText2Col = INVALID_INDEX;
  private int mText2UrlCol = INVALID_INDEX;
  private int mIconName1Col = INVALID_INDEX;
  private int mIconName2Col = INVALID_INDEX;
  private int mFlagsCol = INVALID_INDEX;

  // private final Runnable mStartSpinnerRunnable;
  // private final Runnable mStopSpinnerRunnable;

  /**
   * The amount of time we delay in the filter when the user presses the delete key.
   */
  //private static final long DELETE_KEY_POST_DELAY = 500L;

  public SuggestionsAdapter(Context context, SearchView searchView,
                            WeakHashMap<String, Drawable.ConstantState> outsideDrawablesCache) {
    super(context,
        R.layout.abs__search_dropdown_item_icons_2line,
        null,   // no initial cursor
        true);  // auto-requery
    mSearchManager = (SearchManager) mContext.getSystemService(Context.SEARCH_SERVICE);
    mProviderContext = mContext;
    mSearchView = searchView;

    mOutsideDrawablesCache = outsideDrawablesCache;

    // mStartSpinnerRunnable = new Runnable() {
    // public void run() {
    // // mSearchView.setWorking(true); // TODO:
    // }
    // };
    //
    // mStopSpinnerRunnable = new Runnable() {
    // public void run() {
    // // mSearchView.setWorking(false); // TODO:
    // }
    // };

    // delay 500ms when deleting
//  TODO  getFilter().setDelayer(new Filter.Delayer() {
//
//      private int mPreviousLength = 0;
//
//      public long getPostingDelay(CharSequence constraint) {
//        if (constraint == null) return 0;
//
//        long delay = constraint.length() < mPreviousLength ? DELETE_KEY_POST_DELAY : 0;
//        mPreviousLength = constraint.length();
//        return delay;
//      }
//    });
  }

  /**
   * Enables query refinement for all suggestions. This means that an additional icon
   * will be shown for each entry. When clicked, the suggested text on that line will be
   * copied to the query text field.
   * <p>
   *
   * @param refineWhat which queries to refine. Possible values are {@link #REFINE_NONE},
   * {@link #REFINE_BY_ENTRY}, and {@link #REFINE_ALL}.
   */
  public void setQueryRefinement(int refineWhat) {
    mQueryRefinement = refineWhat;
  }

  /**
   * Returns the current query refinement preference.
   * @return value of query refinement preference
   */
  public int getQueryRefinement() {
    return mQueryRefinement;
  }

  /**
   * Overridden to always return <code>false</code>, since we cannot be sure that
   * suggestion sources return stable IDs.
   */
  @Override
  public boolean hasStableIds() {
    return false;
  }

  /**
   * Use the search suggestions provider to obtain a live cursor.  This will be called
   * in a worker thread, so it's OK if the query is slow (e.g. round trip for suggestions).
   * The results will be processed in the UI thread and changeCursor() will be called.
   */
  @Override
  public Cursor runQueryOnBackgroundThread(CharSequence constraint) {
    if (DBG) Log.d(LOG_TAG, "runQueryOnBackgroundThread(" + constraint + ")");
    String query = (constraint == null) ? "" : constraint.toString();
    /**
     * for in app search we show the progress spinner until the cursor is returned with
     * the results.
     */
    Cursor cursor = null;
    if (mSearchView.getVisibility() != View.VISIBLE
        || mSearchView.getWindowVisibility() != View.VISIBLE) {
      return null;
    }
    //mSearchView.getWindow().getDecorView().post(mStartSpinnerRunnable); // TODO:
    try {
      cursor = getSuggestions(query, QUERY_LIMIT);
      // trigger fill window so the spinner stays up until the results are copied over and
      // closer to being ready
      if (cursor != null) {
        cursor.getCount();
        return cursor;
      }
    } catch (RuntimeException e) {
      Log.w(LOG_TAG, "Search suggestions query threw an exception.", e);
    }
    // If cursor is null or an exception was thrown, stop the spinner and return null.
    // changeCursor doesn't get called if cursor is null
    // mSearchView.getWindow().getDecorView().post(mStopSpinnerRunnable); // TODO:
    return null;
  }

  public Cursor getSuggestions(String query, int limit) {
    Uri.Builder uriBuilder = new Uri.Builder()
        .scheme(ContentResolver.SCHEME_CONTENT)
        .query("")  // TODO: Remove, workaround for a bug in Uri.writeToParcel()
        .fragment("");  // TODO: Remove, workaround for a bug in Uri.writeToParcel()

    // append standard suggestion query path
    uriBuilder.appendPath(SearchManager.SUGGEST_URI_PATH_QUERY);

    // inject query, either as selection args or inline
    uriBuilder.appendPath(query);

    if (limit > 0) {
      uriBuilder.appendQueryParameter(SearchManager.SUGGEST_PARAMETER_LIMIT, String.valueOf(limit));
    }

    Uri uri = uriBuilder.build();

    // finally, make the query
    return mContext.getContentResolver().query(uri, null, null, null, null);
  }

  public void close() {
    if (DBG) Log.d(LOG_TAG, "close()");
    changeCursor(null);
    mClosed = true;
  }

  @Override
  public void notifyDataSetChanged() {
    if (DBG) Log.d(LOG_TAG, "notifyDataSetChanged");
    super.notifyDataSetChanged();

    // mSearchView.onDataSetChanged(); // TODO:

    updateSpinnerState(getCursor());
  }

  @Override
  public void notifyDataSetInvalidated() {
    if (DBG) Log.d(LOG_TAG, "notifyDataSetInvalidated");
    super.notifyDataSetInvalidated();

    updateSpinnerState(getCursor());
  }

  private void updateSpinnerState(Cursor cursor) {
    Bundle extras = cursor != null ? cursor.getExtras() : null;
    if (DBG) {
      Log.d(LOG_TAG, "updateSpinnerState - extra = "
          + (extras != null
          ? extras.getBoolean(SearchManager.CURSOR_EXTRA_KEY_IN_PROGRESS)
          : null));
    }
    // Check if the Cursor indicates that the query is not complete and show the spinner
    if (extras != null
        && extras.getBoolean(SearchManager.CURSOR_EXTRA_KEY_IN_PROGRESS)) {
      // mSearchView.getWindow().getDecorView().post(mStartSpinnerRunnable); // TODO:
      return;
    }
    // If cursor is null or is done, stop the spinner
    // mSearchView.getWindow().getDecorView().post(mStopSpinnerRunnable); // TODO:
  }

  /**
   * Cache columns.
   */
  @Override
  public void changeCursor(Cursor c) {
    if (DBG) Log.d(LOG_TAG, "changeCursor(" + c + ")");

    if (mClosed) {
      Log.w(LOG_TAG, "Tried to change cursor after adapter was closed.");
      if (c != null) c.close();
      return;
    }

    try {
      super.changeCursor(c);

      if (c != null) {
        mText1Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_1);
        mText2Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_2);
        mText2UrlCol = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_2_URL);
        mIconName1Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_ICON_1);
        mIconName2Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_ICON_2);
        mFlagsCol = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_FLAGS);
      }
    } catch (Exception e) {
      Log.e(LOG_TAG, "error changing cursor and caching columns", e);
    }
  }

  /**
   * Tags the view with cached child view look-ups.
   */
  @Override
  public View newView(Context context, Cursor cursor, ViewGroup parent) {
    View v = super.newView(context, cursor, parent);
    v.setTag(new ChildViewCache(v));
    return v;
  }

  /**
   * Cache of the child views of drop-drown list items, to avoid looking up the children
   * each time the contents of a list item are changed.
   */
  private final static class ChildViewCache {
    public final TextView mText1;
    public final TextView mText2;
    public final ImageView mIcon1;
    public final ImageView mIcon2;
    public final ImageView mIconRefine;

    public ChildViewCache(View v) {
      mText1 = (TextView) v.findViewById(android.R.id.text1);
      mText2 = (TextView) v.findViewById(android.R.id.text2);
      mIcon1 = (ImageView) v.findViewById(android.R.id.icon1);
      mIcon2 = (ImageView) v.findViewById(android.R.id.icon2);
      mIconRefine = (ImageView) v.findViewById(R.id.edit_query);
    }
  }

  @Override
  public void bindView(View view, Context context, Cursor cursor) {
    ChildViewCache views = (ChildViewCache) view.getTag();

    int flags = 0;
    if (mFlagsCol != INVALID_INDEX) {
      flags = cursor.getInt(mFlagsCol);
    }
    if (views.mText1 != null) {
      String text1 = getStringOrNull(cursor, mText1Col);
      setViewText(views.mText1, text1);
    }
    if (views.mText2 != null) {
      // First check TEXT_2_URL
      CharSequence text2 = getStringOrNull(cursor, mText2UrlCol);
      if (text2 != null) {
        text2 = formatUrl(text2);
      } else {
        text2 = getStringOrNull(cursor, mText2Col);
      }

      // If no second line of text is indicated, allow the first line of text
      // to be up to two lines if it wants to be.
      if (TextUtils.isEmpty(text2)) {
        if (views.mText1 != null) {
          views.mText1.setSingleLine(false);
          views.mText1.setMaxLines(2);
        }
      } else {
        if (views.mText1 != null) {
          views.mText1.setSingleLine(true);
          views.mText1.setMaxLines(1);
        }
      }
      setViewText(views.mText2, text2);
    }

    if (views.mIcon1 != null) {
      setViewDrawable(views.mIcon1, getIcon1(cursor), View.INVISIBLE);
    }
    if (views.mIcon2 != null) {
      setViewDrawable(views.mIcon2, getIcon2(cursor), View.GONE);
    }
    if (mQueryRefinement == REFINE_ALL
        || (mQueryRefinement == REFINE_BY_ENTRY
        && (flags & SearchManager.FLAG_QUERY_REFINEMENT) != 0)) {
      views.mIconRefine.setVisibility(View.VISIBLE);
      views.mIconRefine.setTag(views.mText1.getText());
      views.mIconRefine.setOnClickListener(this);
    } else {
      views.mIconRefine.setVisibility(View.GONE);
    }
  }

  public void onClick(View v) {
    Object tag = v.getTag();
    if (tag instanceof CharSequence) {
      mSearchView.onQueryRefine((CharSequence) tag);
    }
  }

  private CharSequence formatUrl(CharSequence url) {
    if (mUrlColor == null) {
      // Lazily get the URL color from the current theme.
      TypedValue colorValue = new TypedValue();
      mContext.getTheme().resolveAttribute(R.attr.textColorSearchUrl, colorValue, true);
      mUrlColor = mContext.getResources().getColorStateList(colorValue.resourceId);
    }

    SpannableString text = new SpannableString(url);
    text.setSpan(new TextAppearanceSpan(null, 0, 0, mUrlColor, null),
        0, url.length(),
        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    return text;
  }

  private void setViewText(TextView v, CharSequence text) {
    // Set the text even if it's null, since we need to clear any previous text.
    v.setText(text);

    if (TextUtils.isEmpty(text)) {
      v.setVisibility(View.GONE);
    } else {
      v.setVisibility(View.VISIBLE);
    }
  }

  private Drawable getIcon1(Cursor cursor) {
    if (mIconName1Col == INVALID_INDEX) {
      return null;
    }
    String value = cursor.getString(mIconName1Col);
    Drawable drawable = getDrawableFromResourceValue(value);
    if (drawable != null) {
      return drawable;
    }
    return getDefaultIcon1(cursor);
  }

  private Drawable getIcon2(Cursor cursor) {
    if (mIconName2Col == INVALID_INDEX) {
      return null;
    }
    String value = cursor.getString(mIconName2Col);
    return getDrawableFromResourceValue(value);
  }

  /**
   * Sets the drawable in an image view, makes sure the view is only visible if there
   * is a drawable.
   */
  private void setViewDrawable(ImageView v, Drawable drawable, int nullVisibility) {
    // Set the icon even if the drawable is null, since we need to clear any
    // previous icon.
    v.setImageDrawable(drawable);

    if (drawable == null) {
      v.setVisibility(nullVisibility);
    } else {
      v.setVisibility(View.VISIBLE);

      // This is a hack to get any animated drawables (like a 'working' spinner)
      // to animate. You have to setVisible true on an AnimationDrawable to get
      // it to start animating, but it must first have been false or else the
      // call to setVisible will be ineffective. We need to clear up the story
      // about animated drawables in the future, see http://b/1878430.
      drawable.setVisible(false, false);
      drawable.setVisible(true, false);
    }
  }

  /**
   * Gets the text to show in the query field when a suggestion is selected.
   *
   * @param cursor The Cursor to read the suggestion data from. The Cursor should already
   *        be moved to the suggestion that is to be read from.
   * @return The text to show, or <code>null</code> if the query should not be
   *         changed when selecting this suggestion.
   */
  @Override
  public CharSequence convertToString(Cursor cursor) {
    if (cursor == null) {
      return null;
    }

    String query = getColumnString(cursor, SearchManager.SUGGEST_COLUMN_QUERY);
    if (query != null) {
      return query;
    }

    return null;
  }

  /**
   * This method is overridden purely to provide a bit of protection against
   * flaky content providers.
   *
   * @see android.widget.ListAdapter#getView(int, View, ViewGroup)
   */
  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    try {
      return super.getView(position, convertView, parent);
    } catch (RuntimeException e) {
      Log.w(LOG_TAG, "Search suggestions cursor threw exception.", e);
      // Put exception string in item title
      View v = newView(mContext, mCursor, parent);
      if (v != null) {
        ChildViewCache views = (ChildViewCache) v.getTag();
        TextView tv = views.mText1;
        tv.setText(e.toString());
      }
      return v;
    }
  }

  /**
   * Gets a drawable given a value provided by a suggestion provider.
   *
   * This value could be just the string value of a resource id
   * (e.g., "2130837524"), in which case we will try to retrieve a drawable from
   * the provider's resources. If the value is not an integer, it is
   * treated as a Uri and opened with
   * {@link ContentResolver#openOutputStream(android.net.Uri, String)}.
   *
   * All resources and URIs are read using the suggestion provider's context.
   *
   * If the string is not formatted as expected, or no drawable can be found for
   * the provided value, this method returns null.
   *
   * @param drawableId a string like "2130837524",
   *        "android.resource://com.android.alarmclock/2130837524",
   *        or "content://contacts/photos/253".
   * @return a Drawable, or null if none found
   */
  private Drawable getDrawableFromResourceValue(String drawableId) {
    if (drawableId == null || drawableId.length() == 0 || "0".equals(drawableId)) {
      return null;
    }
    try {
      // First, see if it's just an integer
      int resourceId = Integer.parseInt(drawableId);
      // It's an int, look for it in the cache
      String drawableUri = ContentResolver.SCHEME_ANDROID_RESOURCE
          + "://" + mProviderContext.getPackageName() + "/" + resourceId;
      // Must use URI as cache key, since ints are app-specific
      Drawable drawable = checkIconCache(drawableUri);
      if (drawable != null) {
        return drawable;
      }
      // Not cached, find it by resource ID
      drawable = mProviderContext.getResources().getDrawable(resourceId);
      // Stick it in the cache, using the URI as key
      storeInIconCache(drawableUri, drawable);
      return drawable;
    } catch (NumberFormatException nfe) {
      // It's not an integer, use it as a URI
      Drawable drawable = checkIconCache(drawableId);
      if (drawable != null) {
        return drawable;
      }
      Uri uri = Uri.parse(drawableId);
      drawable = getDrawable(uri);
      storeInIconCache(drawableId, drawable);
      return drawable;
    } catch (Resources.NotFoundException nfe) {
      // It was an integer, but it couldn't be found, bail out
      Log.w(LOG_TAG, "Icon resource not found: " + drawableId);
      return null;
    }
  }

  /**
   * Gets a drawable by URI, without using the cache.
   *
   * @return A drawable, or {@code null} if the drawable could not be loaded.
   */
  private Drawable getDrawable(Uri uri) {
    try {
      String scheme = uri.getScheme();
      if (ContentResolver.SCHEME_ANDROID_RESOURCE.equals(scheme)) {
        // Load drawables through Resources, to get the source density information
        try {
          return getTheDrawable(uri);
        } catch (Resources.NotFoundException ex) {
          throw new FileNotFoundException("Resource does not exist: " + uri);
        }
      } else {
        // Let the ContentResolver handle content and file URIs.
        InputStream stream = mProviderContext.getContentResolver().openInputStream(uri);
        if (stream == null) {
          throw new FileNotFoundException("Failed to open " + uri);
        }
        try {
          return Drawable.createFromStream(stream, null);
        } finally {
          try {
            stream.close();
          } catch (IOException ex) {
            Log.e(LOG_TAG, "Error closing icon stream for " + uri, ex);
          }
        }
      }
    } catch (FileNotFoundException fnfe) {
      Log.w(LOG_TAG, "Icon not found: " + uri + ", " + fnfe.getMessage());
      return null;
    }
  }

  public Drawable getTheDrawable(Uri uri) throws FileNotFoundException {
    String authority = uri.getAuthority();
    Resources r;
    if (TextUtils.isEmpty(authority)) {
      throw new FileNotFoundException("No authority: " + uri);
    } else {
      try {
        r = mContext.getPackageManager().getResourcesForApplication(authority);
      } catch (NameNotFoundException ex) {
        throw new FileNotFoundException("No package found for authority: " + uri);
      }
    }
    List<String> path = uri.getPathSegments();
    if (path == null) {
      throw new FileNotFoundException("No path: " + uri);
    }
    int len = path.size();
    int id;
    if (len == 1) {
      try {
        id = Integer.parseInt(path.get(0));
      } catch (NumberFormatException e) {
        throw new FileNotFoundException("Single path segment is not a resource ID: " + uri);
      }
    } else if (len == 2) {
      id = r.getIdentifier(path.get(1), path.get(0), authority);
    } else {
      throw new FileNotFoundException("More than two path segments: " + uri);
    }
    if (id == 0) {
      throw new FileNotFoundException("No resource found for: " + uri);
    }
    return r.getDrawable(id);
  }

  private Drawable checkIconCache(String resourceUri) {
    Drawable.ConstantState cached = mOutsideDrawablesCache.get(resourceUri);
    if (cached == null) {
      return null;
    }
    if (DBG) Log.d(LOG_TAG, "Found icon in cache: " + resourceUri);
    return cached.newDrawable();
  }

  private void storeInIconCache(String resourceUri, Drawable drawable) {
    if (drawable != null) {
      mOutsideDrawablesCache.put(resourceUri, drawable.getConstantState());
    }
  }

  /**
   * Gets the left-hand side icon that will be used for the current suggestion
   * if the suggestion contains an icon column but no icon or a broken icon.
   *
   * @param cursor A cursor positioned at the current suggestion.
   * @return A non-null drawable.
   */
  private Drawable getDefaultIcon1(Cursor cursor) {
    // Fall back to a default icon
    return mContext.getPackageManager().getDefaultActivityIcon();
  }

  /**
   * Gets the activity or application icon for an activity.
   * Uses the local icon cache for fast repeated lookups.
   *
   * @param component Name of an activity.
   * @return A drawable, or {@code null} if neither the activity nor the application
   *         has an icon set.
   */
  @SuppressWarnings("unused")
private Drawable getActivityIconWithCache(ComponentName component) {
    // First check the icon cache
    String componentIconKey = component.flattenToShortString();
    // Using containsKey() since we also store null values.
    if (mOutsideDrawablesCache.containsKey(componentIconKey)) {
      Drawable.ConstantState cached = mOutsideDrawablesCache.get(componentIconKey);
      return cached == null ? null : cached.newDrawable(mProviderContext.getResources());
    }
    // Then try the activity or application icon
    Drawable drawable = getActivityIcon(component);
    // Stick it in the cache so we don't do this lookup again.
    Drawable.ConstantState toCache = drawable == null ? null : drawable.getConstantState();
    mOutsideDrawablesCache.put(componentIconKey, toCache);
    return drawable;
  }

  /**
   * Gets the activity or application icon for an activity.
   *
   * @param component Name of an activity.
   * @return A drawable, or {@code null} if neither the acitivy or the application
   *         have an icon set.
   */
  private Drawable getActivityIcon(ComponentName component) {
    PackageManager pm = mContext.getPackageManager();
    final ActivityInfo activityInfo;
    try {
      activityInfo = pm.getActivityInfo(component, PackageManager.GET_META_DATA);
    } catch (NameNotFoundException ex) {
      Log.w(LOG_TAG, ex.toString());
      return null;
    }
    int iconId = activityInfo.getIconResource();
    if (iconId == 0) return null;
    String pkg = component.getPackageName();
    Drawable drawable = pm.getDrawable(pkg, iconId, activityInfo.applicationInfo);
    if (drawable == null) {
      Log.w(LOG_TAG, "Invalid icon resource " + iconId + " for "
          + component.flattenToShortString());
      return null;
    }
    return drawable;
  }

  /**
   * Gets the value of a string column by name.
   *
   * @param cursor Cursor to read the value from.
   * @param columnName The name of the column to read.
   * @return The value of the given column, or <code>null</null>
   *         if the cursor does not contain the given column.
   */
  public static String getColumnString(Cursor cursor, String columnName) {
    int col = cursor.getColumnIndex(columnName);
    return getStringOrNull(cursor, col);
  }

  private static String getStringOrNull(Cursor cursor, int col) {
    if (col == INVALID_INDEX) {
      return null;
    }
    try {
      return cursor.getString(col);
    } catch (Exception e) {
      Log.e(LOG_TAG,
          "unexpected error retrieving valid column from cursor, "
              + "did the remote process die?", e);
      return null;
    }
  }
}
